Various systems are known for a porthole opening toward the outside. These opening portholes generally equip a boat, a camper, or any type of roof for a prefabricated room for example. They are generally openings made in the hull of the boat, or for example in the roof of the camper. These openings are equipped with a transparent or opaque element that is to close this opening or to leave this opening partly open to ventilate the room in the boat or in the camper.
In the traditional systems of a porthole, the installation of the transparent or opaque element on the frame of an opening is a fixed installation in which the element, once in position open toward the outside, cannot be moved further, and in particular the inclined surface formed by this element in the open position relative to the wall of the camper or of the boat cannot be further reoriented.
When the element is opened in the direction opposite to the wind direction, the inclined surface formed by the element deflects the wind and consequently does not favor the circulation of air. The element in the open position constitutes a partial shield for the circulation of air and does not allow efficient ventilation of the room equipped with such a porthole. It is essential to be able to optimize the ventilation for a boat or a camper, in particular if the portholes that equip it have a small opening.
Another problem is encountered in the case of traditional vertical portholes when it is necessary to ventilate the room in rainy weather; the porthole in the open position lets the rain come into the room when the element is opened toward the rain.